From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4F17F256C79; Thu, 17 Apr 2025 17:59:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744912773; cv=none; b=UT2puOzru8uFK3SzpksBiyVW8b+SyD03ImRonDU8obHEuGpGXV9F5qUkBNbjqWsWRSyUfGVQxRS9D8+7d0uPfmI81c4YHfXKMBlaKZhJGpzp8A+t3SPDGMmkj0wyLdrM9KgGSQUpw9cdIoAZL2mBhEhtEgXnlTkopNazLVFTPek= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744912773; c=relaxed/simple; bh=0FiDL+E4XE5fnVkoiv2AutWNOT/QBC8ChPCdAL8FOX8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=M/Jb2KzGLHFCmlRcTy6a5R/1SR2pDyw6nzozp4yihrLw4oZGlpWuSPGa9J2WozscLiAtQPIs1/yhN0vEvvqE21+ruXDj8BquTYVy0ts8u1Q7+9ecngo+7XAcS1eOK8fQRKVaPt+S7m4/mvIJTEAsTSFK+0ShGdY6H0V4KGknRtI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ii65iUj0; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ii65iUj0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CC751C4CEE4; Thu, 17 Apr 2025 17:59:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1744912773; bh=0FiDL+E4XE5fnVkoiv2AutWNOT/QBC8ChPCdAL8FOX8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ii65iUj0UOLstGCx2iMZmS6FssztDOuqsgtjYAVi5lCbYr2fRsbw/eVp3fdUABKlf hjJLBKXjexBYyENi1Lsd9Z7mNbC/3N+ot7AhC5TBo5T0lSDEXeOlzPkhuIdf/CXt0Q 8R0oinLp6amPa3WbWTNyhL0caPv6gZEz87Csoe0g= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Philip Pemberton , Damien Le Moal , Niklas Cassel , Sasha Levin Subject: [PATCH 6.14 119/449] ata: libata-eh: Do not use ATAPI DMA for a device limited to PIO mode Date: Thu, 17 Apr 2025 19:46:47 +0200 Message-ID: <20250417175122.757461413@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250417175117.964400335@linuxfoundation.org> References: <20250417175117.964400335@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Niklas Cassel [ Upstream commit 91ec84f8eaddbc93d7c62e363d68aeb7b89879c7 ] atapi_eh_request_sense() currently uses ATAPI DMA if the SATA controller has ATA_FLAG_PIO_DMA (PIO cmds via DMA) set. However, ATA_FLAG_PIO_DMA is a flag that can be set by a low-level driver on a port at initialization time, before any devices are scanned. If a controller detects a connected device that only supports PIO, we set the flag ATA_DFLAG_PIO. Modify atapi_eh_request_sense() to not use ATAPI DMA if the connected device only supports PIO. Reported-by: Philip Pemberton Closes: https://lore.kernel.org/linux-ide/c6722ee8-5e21-4169-af59-cbbae9edc02f@philpem.me.uk/ Tested-by: Philip Pemberton Reviewed-by: Damien Le Moal Link: https://lore.kernel.org/r/20250221015422.20687-2-cassel@kernel.org Signed-off-by: Niklas Cassel Signed-off-by: Sasha Levin --- drivers/ata/libata-eh.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c index 3b303d4ae37a0..16cd676eae1f9 100644 --- a/drivers/ata/libata-eh.c +++ b/drivers/ata/libata-eh.c @@ -1542,8 +1542,15 @@ unsigned int atapi_eh_request_sense(struct ata_device *dev, tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE; tf.command = ATA_CMD_PACKET; - /* is it pointless to prefer PIO for "safety reasons"? */ - if (ap->flags & ATA_FLAG_PIO_DMA) { + /* + * Do not use DMA if the connected device only supports PIO, even if the + * port prefers PIO commands via DMA. + * + * Ideally, we should call atapi_check_dma() to check if it is safe for + * the LLD to use DMA for REQUEST_SENSE, but we don't have a qc. + * Since we can't check the command, perhaps we should only use pio? + */ + if ((ap->flags & ATA_FLAG_PIO_DMA) && !(dev->flags & ATA_DFLAG_PIO)) { tf.protocol = ATAPI_PROT_DMA; tf.feature |= ATAPI_PKT_DMA; } else { -- 2.39.5